Generate Bulletproofs(+) generators at compile time

Creates a new monero-generators crate so the monero crate can run the 
code in question at build time.

Saves several seconds from running the tests.

Closes https://github.com/serai-dex/serai/issues/101.

processor/src/coin/monero.rs

@@ -7,7 +7,6 @@ use transcript::RecommendedTranscript;
 use frost::{curve::Ed25519, FrostKeys};
 
 use monero_serai::{
-  ringct::bulletproofs::Bulletproofs,
   transaction::Transaction,
   rpc::Rpc,
   wallet::{
@@ -69,14 +68,7 @@ pub struct Monero {
 
 impl Monero {
   pub async fn new(url: String) -> Monero {
-    let view = view_key::<Monero>(0).0;
-    let res = Monero { rpc: Rpc::new(url), view };
-
-    // Initialize Bulletproofs now to prevent the first call from taking several seconds
-    // TODO: Do this for both, unless we're sure we're only working on a single protocol
-    Bulletproofs::init(res.rpc.get_protocol().await.unwrap().bp_plus());
-
-    res
+    Monero { rpc: Rpc::new(url), view: view_key::<Monero>(0).0 }
   }
 
   fn view_pair(&self, spend: dfg::EdwardsPoint) -> ViewPair {

processor/src/wallet.rs

@@ -86,7 +86,7 @@ impl CoinDb for MemCoinDb {
   fn add_output<O: Output>(&mut self, output: &O) -> bool {
     // This would be insecure as we're indexing by ID and this will replace the output as a whole
     // Multiple outputs may have the same ID in edge cases such as Monero, where outputs are ID'd
-    // by key image, not by hash + index
+    // by output key, not by hash + index
     // self.outputs.insert(output.id(), output).is_some()
     let id = output.id().as_ref().to_vec();
     if self.outputs.contains_key(&id) {